Microseismic monitoring can be used for monitoring hydraulic fracture stimulation treatments in unconventional fields, as well as reservoir monitoring, carbon dioxide sequestration, gas storage, and other applications. In the example of hydraulic fracture stimulation, the treatments cause fractures to propagate in the formation, with the fracturing in turn generating microseismic events that act as a source for seismic waves that also propagate in the formation. Receiver sensor arrays (e.g., geophones) can be positioned, generally in a monitoring borehole or along the Earth's surface, to detect and record the arrival of the seismic waves.
Based on a model of the relevant subterranean volume, the characteristics of the waveform recorded by the receivers may be used, in a process known as inversion, to determine information about the source of the seismic waves (e.g., fracture propagation). Such information may include the general location of the event, moment tensors, and other information. Generally, the inversion process includes considering direct-arrival compression waves and shear waves (both Sh and Sv arrivals).
Experimental design methods have been applied in the survey design of microseismic monitoring projects. Those techniques can involve, for example, choosing or modifying the location, type, and/or configuration of geophones or other sensors, or arrays of those sensors, to try to arrive at a desired sensitivity or accuracy for the overall detection configuration. These studies allow different experiment setups to be tested statistically, to find a desired or advantageous experimental setup. These can be very successful but in practice, they can take a large amount of work to set up the parameters. Fielding the appropriate sensor and other hardware, and adjusting other parameters, can involve appreciable cost and time. Further, it may be difficult to make adjustments to apply in a variety of different scenarios without well-defined or constrained knowledge of input parameters.